Tolerance to Sand Burial, Trampling, and Drought of Two Subarctic Coastal Plant Species (<i>Leymus mollis</i> and <i>Trisetum spicatum</i>)

Abstract

In order to ensure the sustainable development of the North, increased anthropogenic pressure on subarctic environments must be accompanied by appropriate restoration techniques. Locally adapted restoration guidelines need to rely on sound ecological knowledge of the species used in restoration trials. We evaluate the tolerance (emergence and biomass production) of two coastal species (Leymus mollis and Trisetum spicatum) to sand burial, trampling, and drought, all major constraints to plant colonization in the village of Whapmagoostui-Kuujjuarapik in subarctic Quebec. In three 11-week greenhouse experiments, plants were submitted to three intensities of sand burial (0.0, 0.5, and 1.0 cm per week), trampling events (none, once per week, once per day) and drought (50 mL of water every other day, every week, and every other week). While T. spicatum performance decreased under both moderate and high sand burial intensities, L. mollis tolerated moderate burial intensity. Both species were able to sustain trampling, although the performance of T. spicatum was reduced under high trampling intensity. Finally, neither species could tolerate moderate and high drought intensities, suggesting that watering needs to be included in any restoration initiatives. Since L. mollis performed better than T. spicatum in the sand burial experiment, we recommend the use of this species in future small-scale restoration trials.